The present invention relates to a method of controlling the received signal level in a wireless communication device such as a portable telephone set.
Portable telephone sets and other mobile wireless communication devices are sometimes brought close to a base station from which they receive a transmitted signal. As a result, the electric field strength at the receiving antenna may become so strong as to saturate an amplifier that amplifies the received signal, in which case the signal cannot be received correctly.
One conventional solution to this problem employs a variable-gain amplifier, and reduces the operating point of the variable-gain amplifier when the received signal strength increases. A problem with this solution is that a variable-gain amplifier is more complex than a fixed-gain amplifier, and requires complex control circuitry. Various control methods have been employed, but they have generally required special integrated circuits that add unwanted increments to the size, weight, and cost of the wireless communication device.